Method for reconditioning an endoscope in a reconditioning apparatus, and reconditioning apparatus

ABSTRACT

A method for reconditioning an endoscope in a reconditioning apparatus, the method including: connecting an interior of the endoscope to a leakage tester of the reconditioning apparatus; supplying the interior with a fluid at a predefined pressure; carrying out a reconditioning process using a rinsing liquid; monitoring the pressure in the interior of the endoscope during the reconditioning process; and identifying the endoscope as defective if a profile of the pressure deviates from a predefined pressure profile; wherein the predefined pressure profile is determined according to process parameters of the reconditioning process.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is based upon and claims the benefit of priorityfrom PCT/EP2018/064670—filed on Jun. 4, 2018, which claims benefit to DE10 2017 114 816.7 filed on Jan. 28, 2017, the entire contents of each ofwhich are incorporated herein by reference.

BACKGROUND Field

The present disclosure relates to a method for reconditioning anendoscope in a reconditioning apparatus, said method having the stepsof: connecting an interior of the endoscope to a leakage tester of thereconditioning apparatus, supplying the interior with a fluid at apredefined pressure, and carrying out a reconditioning process usingrinsing liquid, wherein the pressure in the interior of the endoscope ismonitored during the reconditioning process, and wherein the endoscopeto be reconditioned is identified as defective if the profile of thepressure deviates from a predefinable or predefined pressure profile.The present disclosure additionally relates to a reconditioningapparatus for endoscopes.

Prior Art

Endoscopes have been used for many years now, especially in medicine, toexamine and/or treat regions that are difficult to access in the body ofa human or animal patient. For this purpose, endoscopes in most caseshave an elongate shaft, at the distal end of which there is an objectivethrough which a region of interest in the body of the patient can beviewed. At the proximal end of the shaft there is in most cases a mainbody which serves for manipulating the endoscope.

Endoscopes often have inner channels through which fluids can beconveyed to the distal end of the endoscope, in order to be releasedthere. Alternatively, by way of corresponding channels, fluids can alsobe taken in at the distal end of the endoscope and aspirated in thedirection of the main body. Furthermore, treatment instruments can beadvanced through corresponding channels of the endoscope to the distalend, in order to perform an intervention at the region of interest inthe body.

Endoscopes are very difficult and therefore expensive to produce. Inorder to keep costs down, endoscopes are therefore used multiple times.This necessitates thorough reconditioning of the endoscopes between twouses, in order to prevent transmission of diseases.

A distinction is made in principle between rigid and flexibleendoscopes. Rigid endoscopes generally have a shaft and channels made ofa medical-grade stainless steel and are largely or completely sealed offby means of cohesively bonded connections. Therefore, rigid endoscopescan be reconditioned without any problem.

By contrast, flexible endoscopes, at least in the region of the shaft,have a sheath and channels made of a flexible plastic. If this plasticbecomes damaged, contaminating material can enter the interior of theendoscope during use, which material is difficult to effectively removeduring the reconditioning. Likewise, during the reconditioning, which inmost cases takes place using various rinsing liquids, it is possible forrinsing liquid to penetrate the interior of the endoscope and causepermanent damage to the latter.

Prior to the reconditioning of flexible endoscopes, it is thereforeessential to check whether the sheath of the endoscope is intact. Forthis purpose, modern reconditioning apparatuses have a leakage tester.

The leakage tester functions according to the principle by which afluid, in most cases air, is supplied to the interior of the endoscopevia a specially provided port. The pressure profile in the interior isthen measured, and the pressure profile is used to conclude whether theendoscope is sufficiently leaktight.

The pressure in the interior of the endoscope is in most casesmaintained during the actual reconditioning, such that no rinsing liquidcan penetrate the interior, even through unobserved microscopic defectsin the plastic sheath.

In the reconditioning of flexible endoscopes, different rinsing liquidsare used in succession at different temperatures. The temperature of thefluid in the interior of the endoscope also increases. In order to avoiddamage to the plastic sheath of the endoscope as a result of theinternal pressure being too high, the pressure is monitored during thereconditioning process. If the pressure rises above an upper limitvalue, some of the fluid is drained off in order to reduce the pressure.

If the temperature drops again, then the pressure in the interior of theendoscope also drops. As soon as the pressure drops below a lower limitvalue, additional fluid is again conveyed into the interior in order tobring the pressure to the setpoint value again.

The leakage tester monitors how long it takes for the setpoint value ofthe pressure to be reached again after a drop in pressure. If this takestoo long, the endoscope is identified as defective and thereconditioning process is discontinued.

A drop in pressure in the interior of the endoscope can likewise becaused by a loss of leaktightness of the plastic sheath. The leakagetester therefore likewise monitors how often the pressure drops belowthe lower limit value. If this happens too often, the endoscope islikewise identified as defective.

The limit values at which the leakage tester identifies an endoscope asdefective generally have a certain tolerance, and so identificationerrors should be avoided. However, on account of this tolerance, theability of the leak tester to detect very slight losses of leaktightnessis limited.

SUMMARY

It is therefore an object to make available a method for reconditioningendoscopes in a reconditioning apparatus, and also a correspondingreconditioning apparatus which is improved in respect of one or more ofthe problems described.

According to one embodiment , such object can be achieved by a methodfor reconditioning an endoscope in a reconditioning apparatus, saidmethod having the steps of: connecting an interior of the endoscope to aleakage tester of the reconditioning apparatus, supplying the interiorwith a fluid at a predefined pressure, and carrying out a reconditioningprocess using rinsing liquid, wherein the pressure in the interior ofthe endoscope is monitored during the reconditioning process, andwherein the endoscope to be reconditioned is identified as defective ifthe profile of the pressure deviates from a predefined pressure profile,wherein the predefined pressure profile is determined according toprocess parameters of the reconditioning process.

By the described measure, fluctuations of the pressure profile that arecaused by process parameters of the reconditioning process can bedifferentiated from those fluctuations of the pressure profile that arecaused by loss of leaktightness of the endoscope. In this way, theability of the leakage tester to identify loss of leaktightness of theendoscope can be improved.

In the method, fluid can be drained from the interior of the endoscopeif the pressure exceeds an upper limit value. This can prevent theendoscope from being damaged by too high a pressure in its interior, forexample if the pressure rises through an increase in temperature.

Additionally or alternatively, additional fluid can be introduced intothe interior of the endoscope if the pressure drops below a lower limitvalue. It is thus ensured that a sufficient pressure is maintained inthe interior of the endoscope even after a drop in pressure, for exampleafter a drop in the temperature. In this way, it is possible to preventrinsing liquid from entering the interior of the endoscope throughmicroscopic losses of leaktightness in the endoscope.

In an embodiment of the method, the predefined pressure profile isdistinguished by a time that should be the maximum needed to bring thepressure to a setpoint value after the pressure has dropped below thelower limit value. If additional fluid is introduced through the leakagetester into the interior of the endoscope, then the pressure must riseaccordingly and reach a setpoint value within a predefined time.However, if the pressure does not reach the setpoint value within apredefined time, this indicates a loss of leaktightness of theendoscope.

According to a further embodiment of the method, the predefined pressureprofile is distinguished by a maximum frequency at which the pressure isallowed to drop below the lower limit value. For technical reasons, aslow drop in pressure caused by system-inherent loss of leaktightness isnot completely avoidable. With a known operating time of areconditioning process and an admissible pressure drop rate, it ispossible to determine how often the pressure may drop below the lowerlimit value during the reconditioning process. If the pressurefrequently drops below the lower limit value during the reconditioningprocess, this is an indicator of inadmissible loss of leaktightness ofthe endoscope.

In a variation of the method, the process parameters can comprise thetemperature of the rinsing liquid. During the reconditioning process,the rinsing liquid contacts and flows through the endoscope and therebyinfluences the temperature of the fluid in the interior of theendoscope, hence also the pressure thereof. By taking the temperature ofthe rinsing liquid into consideration in the determination of anadmissible pressure profile, temperature-induced pressure fluctuationscan be better distinguished from pressure fluctuations caused by loss ofleaktightness.

The process parameters can comprise the profile of the temperature ofthe rinsing liquid. In this way, the sensitivity in the detection ofloss of leaktightness can be further enhanced.

In the method, the temperature or the temperature profile of the rinsingliquid can be determined by means of sensors provided in thereconditioning apparatus. Such sensors are present anyway in thereconditioning apparatus in order to control the temperature of therinsing liquid according to the requirements of the reconditioningprocess.

Alternatively or additionally, the temperature or the temperatureprofile of the rinsing liquid can be determined on the basis of asetpoint temperature or setpoint temperature profile stored in acontroller of the reconditioning apparatus. In this way, the datacommunication required during the reconditioning process, between thecontroller and the leakage tester, can be reduced, since the admissiblepressure profile can already be determined at the start of thereconditioning process without requiring access to real-time data fromsensors. In the method, several reconditioning programs for differentendoscope types and/or different kinds and/or extents of soiling arestored in the controller of the reconditioning apparatus, areconditioning program is selected at the start of the reconditioning ofthe endoscope, and a temperature profile, stored for the selectedreconditioning program, of the rinsing liquid is used to establish thepredefined or predefinable pressure profile. In this way, the detectionof loss of leaktightness can take place optimally on an individual basisfor each reconditioning process that is to be carried out.

According to a further embodiment, such object can be achieved by areconditioning apparatus for endoscopes, having a reconditioningassembly, a controller and a leakage tester, which reconditioningapparatus is configured to carry out a method according to the abovedescription. As regards the effects and advantages thereby achieved,explicit reference is made to what has been set out above.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments are explained in more detail below with reference to anumber of exemplary figures, in which:

FIG. 1 illustrates a structure of a reconditioning apparatus forendoscopes,

FIG. 2 illustrates a sequence of a reconditioning process,

FIG. 3 illustrates a graphical representation of a profile of thetemperature and of the internal pressure during a process ofreconditioning an intact endoscope,

FIG. 4 illustrates a graphical representation of a profile of thetemperature and of the internal pressure during a process ofreconditioning a defective endoscope.

DETAILED DESCRIPTION

A structure of a reconditioning apparatus for endoscopes is shown inFIG. 1. The reconditioning apparatus 1 has a rinsing chamber 2 which canbe closed by a door 3. The reconditioning apparatus 1 moreover comprisesa rinsing device 4, a leakage tester 5 and a controller 6.

The rinsing device 4 is connected to a spray arm 7 in the rinsingchamber 2. Furthermore, the rinsing device 4 is connected to a rinsedistributor 8. A temperature sensor 9 is arranged on a line leading fromthe rinsing device 4 to the rinse distributor 8. Rinsing device 4, sprayarm 7 and rinse distributor 8 form a reconditioning assembly of thereconditioning apparatus 1.

An endoscope 10 to be reconditioned is arranged in the rinsing chamber2. The endoscope has two inner channels 11, 12 and also an interior 13.For the reconditioning, the channels 11, 12 of the endoscope 10 areconnected to the rinse distributor 8 via hoses 11 a, 12 a. The interior13 of the endoscope 10 is connected to the leakage tester 5 via afurther hose 13 a.

FIG. 2 shows the sequence of a process of reconditioning of theendoscope 10.

In a step 101, the endoscope 10 is connected to the rinse distributor 8and to the leakage tester 5, and the door 3 is then closed.

In a next step 102, an initial leakage test of the endoscope 10 iscarried out. For this purpose, the interior 13 of the endoscope 10 isfilled with a fluid, for example air, through the leakage tester 5 untila predefined setpoint pressure is reached. The pressure is thenmonitored for a predefined time. If the setpoint pressure is not reachedin a predefined time, or if the pressure then drops below a lower limitvalue, the endoscope 10 is identified as defective, and the process isdiscontinued (branch 103 a).

Next, in a step 104, the patency of the channels 11, 12 is checked. Forthis purpose, the controller 6 activates the rinsing device 4 in orderto pump rinsing liquid, for example water, to the rinse distributor 8.The rinse distributor 8 is provided with valves (not shown) which aredriven by the controller 6 such that the rinsing liquid is passedthrough the channels 11, 12 successively. The rinsing device 4 checksthe flow through the channels 11, 12. If the flow through the channels11, 12 is insufficient, the endoscope 10 is identified as being blocked,and the process is discontinued (branch 105 a).

If the channels 11, 12 of the endoscope 10 are unobstructed, theendoscope 10 is treated in a step 106 with cleaning agent. For thispurpose, the rinsing device 4 pumps cleaning agent to the rinsedistributor 8 and to the spray arm 7, such that cleaning agent flowsthrough and wets the interior of the channels 11, 12 and the exterior ofthe endoscope 10.

In a next step 107, residues of the cleaning agent are removed, which isdone by rinsing the channels 11, 12 from the inside, and the endoscope10 from the outside, with water.

In a subsequent process step 108, the channels 11, 12 of the endoscope10 are treated from the inside, and the endoscope 10 from the outside,by a disinfectant.

In a step 109, residues of the disinfectant are in turn rinsed out withwater. In a final step 110, the endoscope 10 is dried.

In parallel with the process steps 104 to 110, a continuous monitoringof the pressure in the interior 13 of the endoscope 10 runs as a loop.For this purpose, it is first of all ascertained whether the pressurehas exceeded an admissible upper limit (branch 120Y). In this case,fluid is drained off in step 121 until the pressure corresponds again tothe setpoint value. Thereafter, the loop begins anew to step 120.

If the pressure is not too high (branch 120N), a check is made toascertain whether the pressure has dropped below a lower limit value atstep 122. If this is not the case (branch 122N), the loop starts anew atstep 120. By contrast, if the pressure has dropped below the lower limitvalue (Branch 122Y), then in step 123 a counter is increased whichindicates the number of drops in pressure. When this counter at step 124reaches a predefined maximum value, the endoscope 10 is identified asdefective and the reconditioning process is discontinued (branch 124 a).

If the maximum value is not yet reached, then in step 125 fluid is againintroduced into the interior 13 of the endoscope 10 in order to increasethe pressure once more to the setpoint pressure. If the setpointpressure is not reached within a predefined time, the endoscope 10 islikewise identified as defective, and the reconditioning process isdiscontinued (branch 126 a). Otherwise, the loop starts anew.

FIG. 3 shows an exemplary profile of a temperature T of the endoscope 10and of the pressure P in the interior 13 of the endoscope, which isreconditioned by the process shown in FIG. 2.

In the upper diagram, the temperature T of the endoscope 10 is shown inan arbitrary scale on the ordinate 201. The time t is shown in anarbitrary scale on the abscissa 202.

A direct measurement of the temperature of the endoscope 10 during thereconditioning process is difficult, since sensors are not generallyprovided for this purpose in the endoscope 10. However, the temperaturecorresponds very precisely to the temperature of the rinsing liquid,which can be measured by the sensor 9 for example. Instead of ameasurement of the temperature, it is also possible to use aninstantaneous temperature setpoint value that is stored in thecontroller 6.

In the lower diagram, the pressure P in the interior 13 of the endoscopeis shown on the ordinate 203, again on an arbitrary scale. The pressureis determined here by sensors in the leakage tester 5. A solidhorizontal line 205 represents a setpoint pressure. Broken lines 206,207 represent an upper and a lower limit value for the pressure.

The time t is again shown on the abscissa 204, wherein the axes 202 and204 are at the same scale. The process steps of the reconditioningprocess are indicated in the diagrams by vertical lines. For greaterclarity, the reference sign belonging to the respective process stepfrom FIG. 2 is indicated again under the axis 204.

In process step 102, no rinsing agent is yet used, and the temperaturetherefore corresponds to the ambient temperature. The pressure initiallyrises from a low starting pressure to the setpoint pressure, while theleakage tester 5 pumps air into the interior 13 of the endoscope 10.After the setpoint pressure is reached, the pressure slowly falls onaccount of system-inherent leakage, but without yet reaching the lowerlimit value 207.

In step 104, water is conveyed through the channels 11, 12 of theendoscope 10, and therefore the temperature drops slightly. This resultsin a corresponding drop of the pressure, such that the pressureapproaches the lower limit value 207 and finally reaches the latter. Theleakage tester 5 registers the first drop in pressure below the lowerlimit value 207. However, on account of the preceding drop intemperature, the drop in pressure is not interpreted by the leakagetester 5 as a defect of the endoscope 10.

The leakage tester 5 then continues to pump air into the interior 13,such that the setpoint pressure 205 is again reached.

In the next process step 106, the endoscope is treated with warmcleaning agent, such that the temperature rises rapidly. The pressurelikewise rises to the upper limit value 206, which causes the leakagetester 105 to release air from the interior 13 of the endoscope 10 untilthe pressure again corresponds to the setpoint pressure 205. From there,the pressure drops slowly again, but without falling below the lowerlimit value 207.

At the start of the process step 107, in which the endoscope 10 istreated with cold water, the temperature and pressure drop sharply, withthe pressure falling below the lower limit value 207. This too is notidentified by the leakage tester 5 as a defect of the endoscope 10,since the drop in pressure is associated with a drop in temperature.

The leakage tester 5 again pumps air into the interior 13 of theendoscope 10 until the setpoint pressure 205 is reached.

In step 108, the disinfection the endoscope 10 takes place, wherein thetemperature is still higher than during step 106. There is again a risein pressure, and air is released.

In step 109, the endoscope 10 is rinsed again with water, such that thetemperature and the pressure drop again. The pressure likewise dropsbelow the lower limit value 207, but the endoscope 10 is correctlyinterpreted as intact.

In the drying step 110, the temperature increases slightly, but this nolonger has any relevant effect on the pressure.

It will be seen that, by taking into consideration the temperature orthe temperature profile in the assessment of the pressure profile, anincorrect assessment of the endoscope 10 as defective can be avoided,without the lower limit value 207 for the pressure having to be set verylow, or a defined number of drops in pressure below the limit value canbe permitted independently of the temperature profile. In this way, thedetection performance of the leakage tester 5 is improved.

FIG. 4 shows the profile of the pressure P and of the temperature Tduring a reconditioning process in which a defect of the endoscope 10occurs.

The axes and process steps correspond to those of FIG. 3. They aretherefore provided with a reference sign in each case increased by 100and are not described all over again.

In the reconditioning process shown in FIG. 4, the disinfection inprocess step 108 at a high temperature has the effect that the sheath ofthe endoscope 10 is corroded by the disinfection solution. This canoccur, for example, when the endoscope 10, after a great number of usesand reconditioning processes, has reached the end of its useful life, orwhen one of the channels 11, 12 has been damaged by a surgicalinstrument during use.

Through the action of the disinfection solution, the sheath of theendoscope becomes porous and air-permeable, such that the pressure inthe interior 13 of the endoscope drops below the lower limit value 307before the end of the process step 108. Since the drop in pressure hasnot been preceded by a corresponding drop in temperature, the leakagetester 5 identifies the defect of the endoscope 10 and discontinues thereconditioning process.

The endoscope 10 can thus be forwarded for inspection and possibly forrepair before large quantities of disinfection solution penetrate theinterior 13 and damage the endoscope 10, possibly irreparably.

While there has been shown and described what is considered to bepreferred embodiments of the invention, it will, of course, beunderstood that various modifications and changes in form or detailcould readily be made without departing from the spirit of theinvention. It is therefore intended that the invention be not limited tothe exact forms described and illustrated, but should be constructed tocover all modifications that may fall within the scope of the appendedclaims.

What is claimed is:
 1. A method for reconditioning an endoscope in areconditioning apparatus, the method comprising: connecting an interiorof the endoscope to a leakage tester of the reconditioning apparatus;supplying the interior with a fluid at a predefined pressure, and;carrying out a reconditioning process using a rinsing liquid; monitoringthe pressure in the interior of the endoscope during the reconditioningprocess; and identifying the endoscope as defective if a profile of thepressure deviates from a predefined pressure profile; wherein thepredefined pressure profile is determined according to processparameters of the reconditioning process.
 2. The method according toclaim 1, further comprising draining fluid from the interior of theendoscope if the pressure exceeds an upper limit value.
 3. The methodaccording to claim 1, further comprising introducing additional fluidinto the interior of the endoscope if the pressure drops below a lowerlimit value.
 4. The method according to claim 3, wherein the predefinedpressure profile is distinguished by a time that is the maximum neededto bring the pressure to a setpoint value after the pressure has droppedbelow the lower limit value.
 5. The method according to claim 3, whereinthe predefined pressure profile is distinguished by a maximum frequencyat which the pressure is allowed to drop below the lower limit value. 6.The method according to claim 1, wherein the process parameters comprisea temperature of the rinsing liquid.
 7. The method according to claim 1,wherein the process parameters comprise a profile of the temperature ofthe rinsing liquid.
 8. The method according to claim 6, wherein thetemperature of the rinsing liquid is determined by sensors provided inthe reconditioning apparatus.
 9. The method according to claim 6,characterized in that the temperature of the rinsing liquid isdetermined on the basis of a setpoint temperature or a setpointtemperature profile stored in a controller of the reconditioningapparatus.
 10. The method according to claim 1, further comprising:storing, in a controller of the reconditioning apparatus, a plurality ofreconditioning programs for different endoscope types and/or differentkinds and/or extents of soiling; selecting a reconditioning program fromthe plurality of reconditioning programs at the start of thereconditioning of the endoscope; and using a temperature profile of therinsing liquid, stored for the selected reconditioning program, toestablish the predefined pressure profile.
 11. A reconditioningapparatus for endoscopes, the reconditioning apparatus comprising: areconditioning assembly; a leak tester; and a controller configured to:connect an interior of the endoscope to the leakage tester; supply aninterior of the endoscope with a fluid at a predefined pressure; carryout a reconditioning process using a rinsing liquid; monitor thepressure in the interior of the endoscope during the reconditioningprocess; and identify the endoscope as defective if a profile of thepressure deviates from a predefined pressure profile; wherein thepredefined pressure profile is determined according to processparameters of the reconditioning process.
 12. The method according toclaim 7, wherein the profile of the temperature of the rinsing liquid isdetermined by sensors provided in the reconditioning apparatus.
 13. Themethod according to claim 7, wherein the profile of the temperature ofthe rinsing liquid is determined on the basis of a setpoint temperatureor a setpoint temperature profile stored in a controller of thereconditioning apparatus.